Top Republican presidential candidates have sought to emphasize their economic and social platforms ahead of the primary vote in South Carolina on Saturday. In Columbia, VOA's Brian Wagner reports the vote is the first in a southern U.S. state, where candidates' views on the military and religion are expected to be key factors.

Republican leaders in South Carolina say Saturday's vote is a key step in the process to select the party's presidential candidate for the November elections. Since former President Ronald Reagan won the South Carolina primary on his way to victory in the 1980 general election, no Republican candidate has captured the White House without winning the state's primary.

Recent opinion polls show the top two candidates are Senator John McCain and former Arkansas governor Mike Huckabee. Both held numerous campaign events across the state ahead of the vote.

Senator McCain has been appealing to the state's large population of military personnel and veterans to say his service during the Vietnam War would help him as commander-in-chief.

"Overall, who is best qualified to take on this titanic struggle against radical Islamic extremists? And I think I am the most qualified," he said.

On the economy, McCain said South Carolina has been a model for other states, because it has attracted new factory jobs to replace work lost when plants closed and moved overseas.

Huckabee has criticized the economic views of his opponents, saying too little attention is being paid to the problems facing families.

"Some of these guys are not listening to them, because families are working harder than they worked a year ago, but they are not necessarily getting ahead," he noted.

At some of his campaign events, Huckabee has sought to appeal to the region's Christian base, by emphasizing his background as a Baptist minister.

Some political analysts have said religion may work against former Massachusetts Governor Mitt Romney, who is Mormon. During a brief stop in the state on Thursday, Romney focused on the need to address a possible recession in the country.

"The consequence of the economy falling into recession is one which can be calculated in large numbers for the government, but in very important, heartfelt changes for the families of America," he said.

Former Senator Fred Thompson from the neighboring state of Tennessee also has campaigned actively in South Carolina and has emphasized shared cultural ties. On Thursday, he addressed the nation's economic troubles. He said economic experts should be allowed to find the solution.

"It just requires strong heads at the table and not snap judgments by politicians on the road, trying to think of something smart to say in 30 seconds," he said.

A new MCClatchy/MSNBC poll shows Senator McCain leading the field with 27 percent support, two points ahead of Huckabee. It shows Romney and Thompson in a close battle for third place as well as limited support for former New York Mayor Rudy Giuliani and Congressman Ron Paul.

South Carolina's Democratic voters will hold a separate presidential primary next Saturday.